Mark Fowler > Test-DatabaseRow-1.04 > Test::DatabaseRow



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Module Version: 1.04   Source   Latest Release: Test-DatabaseRow-2.04


Test::DatabaseRow - simple database tests


 use Test::More tests => 3;
 use Test::DatabaseRow;

 # set the default database handle
 local $Test::DatabaseRow::dbh = $dbh;

 # sql based test
 row_ok( sql   => "SELECT * FROM contacts WHERE cid = '123'",
         tests => [ name => "trelane" ],
         label => "contact 123's name is trelane");

 # test with shortcuts
 row_ok( table => "contacts",
         where => [ cid => 123 ],
         tests => [ name => "trelane" ],
         label => "contact 123's name is trelane");

 # complex test
 row_ok( table => "contacts",
         where => { '='    => { name   => "trelane"            },
                    'like' => { url    => ''   },},

         tests => { '=='   => { cid    => 123,
                                num    => 134                  },
                    'eq'   => { person => "Mark Fowler"        },
                    '=~'   => { road   => qr/Liverpool R.?.?d/ },},

         label => "trelane entered into contacts okay" );


This is a simple module for doing very very simple quick tests on a database, primarily designed to test if a row exists with the correct details in a table or not. For more advanced testing (joins, etc) it's probably easier for you to roll your own tests by hand than use this module.

Exports one test function row_ok. This tests if the first selected row compares to the passed specification.

The row_ok takes named attributes that control which rows in which table it selects, and what tests are carried out on those rows.


The database handle that the test should use. In lieu of this attribute being passed the test will use whatever handle is set in the $Test::DatabaseRow::dbh global variable.


The sql to select the rows you want to check. Some people may prefer to use the table and where arguments (see below) to have the function build their SQL dynamically for them. This can either be just a plain string, or it can be an array ref of which the first element should contain the SQL with placeholders and the remaining elements will be considered bind variables

  # using the plain string version
  row_ok(sql   => "SELECT * FROM contacts WHERE cid = '123'",
         tests => [ name => "Trelane" ]);

  # using placeholders and bind variables
  row_ok(sql   => [ "SELECT * FROM contacts WHERE cid = ?", 123 ],
         tests => [ name => "Trelane" ]);

If you're not using the sql option, then the name of the table the select should be carried out on.


If you're not using the sql option, then a collection of things that you want combined into a WHERE clause in order to select the row that you want to test.

This is normally a hash of hashes. It's a hashref keyed by SQL comparison operators that has in turn values that are further hashrefs of column name and values pairs. This sounds really complicated, but is quite simple once you've been shown an example. If we could get get the data to test with a SQL like so:

    WHERE foo  =    'bar'     AND
          baz  =     23       AND
          fred LIKE 'wilma%'  AND
          age  >=    18

Then we could have the function build that SQL like so:

  row_ok(table => "tablename",
         where => { '='    => { foo  => "bar",
                                baz  => 23,       },
                    'LIKE' => { fred => 'wimla%', },
                    '>='   => { age  => '18',     },});

Note how each different type of comparison has it's own little hashref containing the column name and the value for that column that the associated operator SQL should search for.

This syntax is quite flexible, but can be overkill for simple tests. In order to make this simpler, if you are only using '=' tests you may just pass an arrayref of the columnnames / values. For example, just to test

  SELECT * FROM tablename
    WHERE foo  =     bar     AND
          baz  =     23;

You can simply pass

  row_ok(table => "tablename",
         where => [ foo  => "bar",
                    baz  => 23,    ]);

Which, in a lot of cases, makes things a lot quicker and simpler to write.

NULL values can confuse things in SQL. All you need to remember is that when building SQL statements use undef whenever you want to use a NULL value. Don't use the string "NULL" as that'll be interpreted as the literal string made up of a N, a U and two Ls.

As a special case, using undef either in a = or in the short arrayref form will cause a "IS" test to be used instead of a = test. This means the statements:

  row_ok(table => "tablename",
         where => [ foo  => undef ],)

Will produce:

  SELECT * FROM tablename

The comparisons that you want to run between the expected data and the data in the first line returned from the database. If you do not specify any tests then the test will simply check if any row is returned from the database.

Normally this is a hash of hashes in a similar vein to where. This time the outer hash is keyed by Perl comparison operators, and the inner hashes contain column names and the expected values for these columns. For example:

  row_ok(sql   => $sql,
         tests => { "eq" => { wibble => "wobble",
                              fish   => "fosh",    },
                    "==" => { bob    => 4077       },
                    "=~" => { fred   => qr/barney/ },},);

This checks that the column wibble is the string "wobble", column fish is the string "fosh", column bob is equal numerically to 4077, and that fred contains the text "barney". You may use any infix comparison operator (e.g. "<", ">", "&&", etc, etc) as a test key.

The first comparison to fail (to return false) will cause the whole test to fail, and debug information will be printed out on that comparison.

In a similar fashion to where you can also pass a arrayref for simple comparisons. The function will try and Do The Right Thing with regard to the expected value for that comparison. Any expected value that looks like a number will be compared numerically, a regular expression will be compared with the =~ operator, and anything else will undergo string comparison. The above example therefore could be rewritten:

  row_ok(sql   => $sql,
         tests => [ wibble => "wobble",
                    fish   => "fosh",
                    bob    => 4077,
                    fred   => qr/barney/ ]);

Setting this option to a true value will cause verbose diagnostics to be printed out during any failing tests. You may also enable this feature by setting either $Test::DatabaseRow::verbose variable the TEST_DBROW_VERBOSE environmental variable to a true value.


Sometimes, it's not enough to just use the simple tests that Test::DatabaseRow offers you. In this situation you can use the store_rows function to get at the results that row_ok has extacted from the database. You should pass a reference to an array for the results to be stored in; After the call to row_ok this array will be populated with one hashref per row returned from the database, keyed by column names.

  row_ok(sql => "SELECT * FROM contact WHERE name = 'Trelane'",
         store_rows => \@rows);


The same as store_rows, but only the stores the first row returned in the variable. Instead of passing in an array reference you should pass in either a reference to a hash...

  row_ok(sql => "SELECT * FROM contact WHERE name = 'Trelane'",
         store_rows => \%row);


...or a reference to a scalar which should be populated with a hashref...

  row_ok(sql => "SELECT * FROM contact WHERE name = 'Trelane'",
         store_rows => \$row);


Checking the number of results

By default row_ok just checks the first row returned from the database matches the criteria passed. By setting the parameters below you can also cause the module to check that the correct number of rows are returned from by the select statment (though only the first row will be tested against the test conditions.)


Setting this parameter causes the test to ensure that the database returns exactly this number of rows when the select statement is executed. Setting this to zero allows you to ensure that no matching rows were found by the database, hence this parameter can be used for negative assertions about the database.

  # assert that Trelane is _not_ in the database
  row_ok(sql     => "SELECT * FROM contacts WHERE name = 'Trelane'",
         results => 0 );

  # convience function that does the same thing
  not_row_ok(sql => "SELECT * FROM contacts WHERE name = 'Trelane'")
min_results / max_results

This parameter allows you to test that the database returns at least or no more than the passed number of rows when the select statement is executed.

Other SQL modules

The SQL creation routines that are part of this module are designed primarily with the concept of getting simple single rows out of the database with as little fuss as possible. This having been said, it's quite possible that you need to use a more complicated SQL generation scheme than the one provided.

This module is designed to work (hopefully) reasonably well with the other modules on CPAN that can automatically create SQL for you. For example, SQL::Abstract is a module that can manufacture much more complex select statements that can easily be 'tied in' to row_ok:

  use SQL::Abstract;
  use Test::DatabaseRow;
  my $sql = SQL::Abstract->new();

  # more complex routine to find me heuristically by looking
  # for any one of my nicknames and my street address
  row_ok(sql   => [ $sql->select("contacts",
                                 { name => [ "Trelane",
                                             "MarkF" ],
                                   road => { 'like' => "Liverpool%" },
         tests => [ email => '' ],
         label => "check mark's email address");

utf8 hacks

Often, you may store data utf8 data in your database. However, many modern databases still do not store the metadata to indicate the data stored in them is utf8 and thier DBD drivers may not set the utf8 flag on values returned to Perl. This means that data returned to Perl will be treated as if it is encoded in your normal charecter set rather than being encoded in utf8 and when compared to a byte for byte an identical utf8 string may fail comparison.

    # this will fail incorrectly on data coming back from
    # mysql since the utf8 flags won't be set on returning data
    use utf8;
    row_ok(sql   => $sql,
           tests => [ name => "Napol\x{e9}on" ]);

The solution to this is to use Encode::_utf_on($value) on each value returned from the database, something you will have to do yourself in your application code. To get this module to do this for you you can either pass the force_utf8 flag to row_ok.

    use utf8;
    row_ok(sql        => $sql,
           tests      => [ name => "Napol\x{e9}on" ],
           force_utf8 => 1);

Or set the global $Test::DatabaseRow::force_utf8 variable

   use utf8;
   local $Test::DatabaseRow::force_utf8 = 1;
   row_ok(sql        => $sql,
          tests      => [ name => "Napol\x{e9}on" ]);

Please note that in the above examples with use utf8 enabled I could have typed unicode eacutes into the string directly rather than using the \x{e9} escape sequence, but alas the pod renderer you're using to view this documentation would have been unlikely to render those examples correctly, so I didn't.

Please also note that if you want the debug information that this module creates to be redered to STDERR correctly for your utf8 terminal then you may need to stick

   binmode STDERR, ":utf8";

At the top of your script.


You must pass a sql or where argument to limit what is returned from the table. The case where you don't want to is so unlikely (and it's much more likely that you've written a bug in your test script) that omitting both of these is treated as an error. If you really need to not pass a sql or where argument, do where => [ 1 => 1 ].

We currently only test the first line returned from the database. This probably could do with rewriting so we test all of them. The testing of this data is the easy bit; Printing out useful diagnostic infomation is hard. Patches welcome.

Passing shared variables (variables shared between multiple threads with threads::shared) in with store_row and store_rows and then changing them while row_ok is still executing is just asking for trouble.

The utf8 stuff only really works with perl 5.8 and later. It just goes horribly wrong on earlier perls. There's nothing I can do to correct that. Also, no matter what version of Perl you're running, currently no way provided by this module to force the utf8 flag to be turned on for some fields and not on for others.


Written by Mark Fowler>. Copyright Profero 2003, 2004.

Some code taken from Test::Builder, written by Michael Schwern. Some code taken from Regexp::Common, written by Damian Conway. Neither objected to it's inclusion in this module.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Bugs (and requests for new features) can be reported to the open source development team at Profero though the CPAN RT system:


Test::More, DBI

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